class_docstr: Dataset of penguin tabular data.
  
  From https://www.tensorflow.org/datasets/catalog/penguins.
code: def spec(self):
      return INPUT_SPEC | {
          "species": lit_types.CategoryLabel(vocab=VOCABS["species"])
      }
  
file_path: lit/lit_nlp/examples/datasets/penguin_data.py
imports: from collections.abc import Mapping
  from typing import Optional, Union
  from lit_nlp.api import dataset
  from lit_nlp.api import types
  import tensorflow_datasets
label_desc: Use image node_id 4 for calling the PenguinDataset obj's underlying member method code with example usage: obj.spec() and returns: unknown